woolson



(Model.)

o. C. WooLsoN.

ARMATURE POR ELECTRO MAGNETS.

Patented Ma.1.`28,l882

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UNITED STATES PATENT OFFICE.

OROSOO GWOOLSON, OF NEYARK, NEV JERSEY, ASSIGNOR TO CHARLES A. CHEEVEE, TRUSTEE, OF NEYV YORK, N. Y.

ARMATURE FOR ,ELECTRO-MAGNETS.

SPECIFICATION forming part of Letters Patent No. 255,749, dated March 28, 1882.

(Model.)

To all whom it may concern:

Be it known that I, Onosoo C. WooLsoN, a citizen of the United States, residing at Newark, in the county of Essex and State of New Jersey, have invented certain neuT and useful Improvements in Armatures for Electro- Magnets,of which improvements the following L is a specification.

The object of my invention is to attain an 1o armature (composed of separable disconnected sections) movable freely laterally relatively to its supports, so as when properly energized to be held in frictional contact with a surface against which it rests, iu order to hold said i5 surface and armature in a xed relation to each other, and to be automatically released therefrom when demagnetized, so as to allow the surface and armature to move longitudi nally relatively to each other. Such an armazo ture is capable of numerous useful applications inf the arts, which will readily suggest themselves to persons skilled therein. As one especially valuable application I may mention its adaptability to the automatic control of the carbons of an electric light, which adaptation will form the subject of another application for Letters Patent.

The details of construction of my improved armature may be modified in various ways 3o without departing from the principle of my invention.

lSome of the parts ot' the apparatus herein described may be used without the others, and in organizations differing in their details of construction from those herein set forth.

The accompanying drawings represent so much of my improved apparatus as is necessary to illustrate the subject'matter claimed, and show various modifications of the inven- 40 tion.

Figure l represents a central longitudinal section through the apparatus; Fig. 2, a transverse section therethrough on the line 2 2 of Fig.1; Fig. 3, a central longitudinal section through another form of the apparatus, Fig. 4, a transverse section therethrough on the line 4 4 ot' Fig. 3; and Fig. 5 represents a corresponding transverse section through another modication ot' the apparatus.

Fig. l shows an ordinary maguetspool, M, with a coil or helix, m, of properly-insulated wire wound thereon, so as to diminish in diameter from one end to the other. In this instance the coil is shown as diminishing by steps; but obviously the wire might be wound in a vconical form. The effect of this winding is ot' course to produce a greater energizing etect at one end of the coil than at the other, as is well understood, or, in other words, to transfer the center of the magnetic field pro- 6o portiouately nearer to the larger end ot' the coil. The spool is ofcourse to be secured in a suitable frame. A supporting-frame (shown as made in the form ot' a tube, O, ot'non-magnetic metal, and capable of moving freely endwise through the spool) is connected with the object to be sustained, suspended or acted upon (not necessary to be shown here) in wellknown ways. A skeleton-frame would answer thesamepurpose. Acageorcarriage,F,issus- '1o pended within this tube by a rod,chaiu, or support, S. This cage may be of magnetic or nonmagnetic metal, as preferred. It is shown as constructed in the form of a spool, around which are arranged a series of disconnected rods, A,ofmagnetic metalsuch, for instance, as soft iron, or they may,it` preferred, consist of permanent magnets. "Ihese rods are not hinged or connected with their supports, but

are prevented from longitudinal play, except 8o Y to a slight extent, by the heads or flanges ot' the cage or carriage F, above mentioned. They are, however, capable of .moving freely laterally in the space between the tube and cage.

When a number ofiron or steel rods ot' small 85 diameter aud ot'equal length are placed loosely within the central opening otl a helix or coil and parallel to its longitudinal axis, and acurrent of electrity is made to traverse the wire ot' the coil, the rods will tend instantly to place 9o themselves as far from the axis of the helix and from each other as possible, and they will therefore assume a position in which they will all be in contact with the inner surface of the helixat ditferentpoiut-s, and will press against it with a degree of force dependent upon the strength of the exciting-current. I avail myself of this principle iu the construction and operation ot' the apparatus hereinbefore described.

`When a current of electricity is passed through the coil,the separable rodsAare caused to press against the inner surface of the supporting fame or tube C, and thus hold it by their frictional contact with a force proportioned to the energy ofthe actuating-current. When this current ceases their contact is released and the tube is again free.

ln addition to the action above described, owing to the fact that in this instance the center ofthe magnetic field, or ofthe magnetic attraction of the helix,is nearer its upper than its lower end, the tirst etfect of the energizing current is a tendency to draw the armatures and cage upward, their frictional contact causing the tube to be lifted with them until they reach the neutral point ofthe magnetic field, or one where the actuatingforces are balanced, when they will be held there as long as the energiziiig-current flows. In order that the lifting action may be exerted, it is of course necessary that the cage should move freely upon the supporting rod or chain S,'as otherwise the clamping action alone would take place. The normal position ot' the cage with reference to the helix or spool may also be adjusted by means ofthe said rod or chain, if desired.

In Figs. 3 and4 the suspended cage or carriagcis shown as consistingofa body, F, (shown in transverse section in Fig. 4,) which body may be either ot' magnetic or non-magnetic metal. The armatures A are retarded in their lateral motions by means of springs P P', secured to suitable heads and passing through openings in the flanges F ofthe carriage, the degree ot' resiliencyof these springs being regulated by means of a screwed spindle, N, working` through a collar, K, to adjust its distance relatively to the flange F of the carriage, and thus alter the length of the operative portion ofthe springs. rlllese adjustments might be etfectedin various otherequivalent well-known ways. These springs, it will be observed, are not at all necessary to the supportotthe separable armature sections or rods A, their essential function being thatot' modifying the action ofthe armature to a certain extent, as above described.

Fig. Srepresen ts a transverse section through another form of compound armature, consisting of a central core, F, surrounded by disconnected separable armature-sections A, preferably ot soft iron, between which are interposed disconnected separable small rods or bars a, which are permanently magnetized. These latter, being constantly magnetic, produce a slight but continuous friction, even when the current is not passing through the helix-a result which is ot' practical utility in lthe operation of certain classes ot' mechanism. rlhe arrangement shown in the tigure may be moditied by constructing the larger armature-sections, A, of steel and rendering them permanently magnetic, and the smaller ones, a., ofsoft iron.

The disconnected separable armaturesections above described in all cases lie (and move laterally) in planes substantially parallel with the axes of their energizing-coils, instead ot' being arranged transversely thereto, as usual heretofore. rlhey are brought, moreover, by magnetic induction or attraction, in direct frictional Contact with the surfaces upon which they are to act without the intervention of gearing or other mechanism. By the term expanding armature,77 then, I mean one composed of disconnected separable sections movable laterally toward and from each other in planes substantially parallel with the axis ot' their energizingcoil.

I am aware that armatures moving transversely to their energizing-coils, and acting through gearing, pivoted levers, or similar devices to clamp the carbons ot' an electriclight, have been used, and do not claim such devices, as they can in no sense be called ex` panding armatures, and differ essentially in principle, function, and operation from my improvement, neither do I claim herein armatures consisting of expansible and collapsible tubes, strips fastenedu at their ends and capa! ble ot' bulging at their centers, or armaturesections pivoted or fastened at one end and capable of moving laterally at the other, as these devices constitute the subject-matter ot' another division ot' this application.

I claim as my invention- 1. The compound armature hereinbefore dcscribed, consisting ot' disconnected sections lying parallel with each other and with their energizing-coil and movable laterally parallel therewith, substantially as herein set forth.

2. The combination, substantially as hereinbefore set forth, of the energizingcoil and the expanding armature-sections inclosed and movable laterally therein parallel, or substantially parallel, with its axis.

3. The combination, substantially as hereinbetore set forth, of the energizing-coil, thc expanding laterally-movable armature-sections inclosed therein, andthe interposed supporting-frame of non-magnetic metal.

4. The combination, substantially as hereinbet'ore set forth, ot' the energizing-coil, the armature-sections movable laterally therein, and its longitudinally-adjustable supportingcage.

5. The combination, substantially as herein vset forth, ofa coil o1' helix, a supportingframe or tube movable therein, a cage or carriage movable in the supporting-frame, and an expanding armature movable in the cage.

6. The combination, substantially as herein set forth, ofa coil or helix, a supporting frame or tube of non-magnetic metal movable therein, a cage or carriage movable in the supporting-frame, and a series of independent armatures movable laterally in and with the cage.

OROSGO C. IOOLSON Witnesses:

W ILLJIRD L. CANDEE, WM. SINCLAIR.

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